public static int surfaceArea(List<List<Integer>> A) {
    // Write your code here
        int front = 0;int side1 = 0;int side2 = 0;int bttm = 0;int back = 0;int top = 0;
        int frontInt = 0;int sideInt = 0;//Internals
        //Side1 and Side2
        side1 = A.get(0).stream().mapToInt(Integer::intValue).sum();
        side2 = A.get(A.size()-1).stream().mapToInt(Integer::intValue).sum();
        int i = 0;
        for(List<Integer> list : A){
            int zeroCount = (int) list.stream().filter(n -> n == 0).count();
            front += list.get(0);//Only works if no empty space..i.e filled with 0 
            top += (list.size()-zeroCount);//Those with 0 height
            bttm = top;
            back += list.get(list.size()-1);
            //Calculate front and side internals
            if(i>0){
                List<Integer> B = A.get(i-1);
                int maxLength = Math.max(list.size(), B.size());

        sideInt += IntStream.range(0, maxLength)
            .map(h -> {
                int a = h < list.size() ? list.get(h) : 0;
                int b = h < B.size() ? B.get(h) : 0;
                return Math.abs(a - b);
            })
            .sum();
            }
            frontInt += IntStream.range(1, list.size())
            .map(k -> Math.abs(list.get(k) - list.get(k - 1)))
            .sum();
            i++;
        }
        System.out.printf("front: %d,side1: %d,side2: %d,back: %d, top: %d, bttm: %d, sideInt: %d, frtInt: %d",front,side1,side2,back,top,bttm,sideInt,frontInt);
        return front+side1+side2+back+top+bttm+sideInt+frontInt;
    }

def surfaceArea(A):
    # Write your code here
    
    f_b=0 #front back
    t_b=0 #top bottom
    l_r=0 # left right
    
    #top and bottom surface area
    t_b = H * W * 2

    
    #Front and Back surface area
    if H==1:
        for j in range(W):
            f_b+=A[0][j]*2
    else:
        for i in range(H):
            for j in range(W):
                if i == H-1:
                    f_b+=A[i][j]
                    f_b+=(abs(A[i][j]-A[i-1][j]))
                elif i != 0:
                    f_b+=(abs(A[i][j]-A[i-1][j]))
                else:
                    f_b+=A[i][j]  
    
    
    #left and right surface area
    if W == 1:
        for i in range(H):
            l_r+=A[i][0]*2
    else:
        for j in range(W):
            for i in range(H):
                if j == W-1:
                    l_r+=A[i][j]
                    l_r+=(abs(A[i][j]-A[i][j-1]))
                elif j !=0:
                    l_r+=(abs(A[i][j]-A[i][j-1]))
                else:
                    l_r+=A[i][j]
    
    return f_b + l_r + t_b

#python 3
def surfaceArea(A):
    # Area of top, bottom, and front
    area = 2 * len(A[0]) * len(A) + sum(A[-1])
    for i, row in enumerate(A):
        #reset h for each row
        h = 0
        for j, stack in enumerate(row):
            #add left edge
            area += abs(stack - h)
            #add back edge
            area += abs(stack - (0 if i == 0 else A[i-1][j]))
            #update h to current stack
            h = stack
        #add right edge of final stack
        area += h
    return area

function surfaceArea(A) {
    let besides = [[1,0],[-1,0],[0,1],[0,-1]]
    let surface = 0
    for(let i=0; i<A.length; i++){
        for(let j=0; j<A[0].length; j++){
            surface += 2
            for(let [r,h] of besides){
               surface += Math.max(A[i][j] - (A[i+r]?.[j+h] || 0), 0);
            }
        }
    }
    return surface
}